Thanks for your question on Healthcare Magic.
I can understand your concern.
Yes, possibility of musculoskeletal pain
due to work out is more.
At your age of 15 years, heart diseases related pain is not possible. So don't worry about it.
Musculoskeletal pain is more likely.
So follow these steps for better symptomatic relief.
1. Avoid heavyweight lifting and strenuous exercise. Avoid heavy work out for few days.
2. Avoid movements causing pain.
3. Avoid bad postures in sleep.
4. Take painkiller like ibuprofen
5. Apply warm water pad on affected areas.
Don't worry, you will be alright with all these.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.